(1) Field of the Invention
This invention relates to the heat transfer printing of fabrics with disperse dyes. More specifically it relates to a pretreatment, crosslinking system that is useful in the screen printing of cellulose-containing textile materials to improve the affinity of such textiles for disperse dyestuffs. The method allows the pretreatment to be applied to a textile in fabricated garment form.
(2) Description of the Prior Art
Heat transfer printing is a process whereby a paper containing disperse dyestuffs on the surface is placed in contact with a suitable material and heated, so that the sublimable dyes are transferred from paper to fabric. Unmodified cellulose cannot be effectively heat transfer printed with disperse dyes because of a lack of affinity. Very little dye is adsorbed by the cellulose, and this small amount is removed upon washing. This is in marked contrast to the effect obtained with some synthetic textiles, such as polyester, which have excellent affinity for disperse dyes.
Lambert, British Pat. No. 1,445,201, has demonstrated that the affinity of a cellulose-containing textile for disperse dyes can be improved by treatment with a methylated melamine-formaldehyde resin in which there are five--CH.sub.2 OCH.sub.3 groups per melamine group. The fabric is printed by heating for 3 minutes at 200.degree.-210.degree. C. with transfer paper containing disperse dyes. This longer printing time is needed because of the use of a weaker catalyst, such as (NH.sub.4)H.sub.2 PO.sub.4, than is usually used for resin finishing of cellulose.
British Pat. No. 1,460,742 teaches that cellulose-containing fabrics can be effectively transfer printed with disperse dyestuffs if the fabric is impregnated with at least one curable resin containing one or more hydroxymethyl, alkoxymethyl or aldehyde groups that are capable of reacting with the disperse dyestuffs. The recommended disperse dyestuffs contain one or more amino, hydroxy, or N-hydroxyalkylamino groups.
In all prior work, no system composed of hexamethoxymethyl melamine, p-toluene sulfonic acid, 2-amino-2-methyl-1-propanol, triethylamine, butoxy, triglycol, and carboxy vinyl polymeric thickener has been employed as a pretreatment for fabric by screen printing the formulation onto the surface of a cellulose-containing garment so as to increase its disperse dye affinity.
Those systems with methylated melamine-formaldehyde resin and other components all teach that the fabric is to be treated by padding with a low viscosity formulation.